When using NVidia drivers instead of generic drivers, I'm unable to run Xfree at 1280x1024, and to force Xfree to run at this resolution, I need to use a custom modeline made my 'gtf' but I'm unsure how to run gtf. Would it be possible for someone to write a custom modeline that will force Xfree at this resolution for me?

However, seeing as you have gtf to begin with, you therefore have X 4.3.0. Right?

If so (well heck, even if not), you can just tell it to use 1280x1024, and then make sure your HorizSync and VertRefresh lines have the correct ranges for your monitor (check the monitor documentation for the correct ranges to use), and it'll use the highest refresh rate it knows about.

Hang on... what happens when you try 1280x1024? It may very well not be the case that you need to write a modeline, but it depends on the reason that mode is getting thrown out -- what's in your X log when you try to use that resolution?

The problem is that none of the possible modes are actually valid. They're either outside the VertRefresh range, or outside the HorizSync range.

This might be because both of those ranges are being adjusted based on EDID information; if this EDID information is incorrect (check your monitor's manual), then use Option "IgnoreEDIDs" (and make sure that you raise your VertRefresh -- having a maximum of 60Hz is very likely WAY too low).